The desperate search for a missing Iowa college student is focused on a vast expanse of dense cornfields.

It's a nightmare facing law enforcement as the hunt for the college sophomore who vanished after going jogging last week intensifies.

Mollie Tibbetts, 20, is a psychology major at the University of Iowa. She was last seen jogging at about 5 p.m. last Wednesday in the small town of Brooklyn, Iowa.

Investigators have been combing through cornfields, but the issue is the fields are incredibly thick. The stalks are about 10 feet tall.

Tibbetts was dog sitting for her boyfriend, Dalton Jack, when she disappeared.

He says he's baffled about his girlfriend's disappearance.

"I have no idea. I'm just kinda putting my trust and faith in the law enforcement,” he told a local news outlet. "I don't know if anything that I say will get that out of some people's mind that I had nothing to do with it."

Her cousin, Morgan Collum, told Inside Edition that the family is going through "a roller coaster" of emotions as they hold out hope for Tibbetts' safe return.

Volunteers have been blanketing the area with missing posters, t-shirts and billboard pleas for help in finding her.

Anyone with information about Tibbetts is asked to call the Poweshiek County Sheriff’s Office at 641-623-5679.